Towards Biosensor Enabled Smart Bandages for Wound Monitoring: Approach and Overview

This work presents an approach towards integrating enzymatic biosensors to monitor wound healing. Levels of uric acid (UA) a metabolic byproduct of purine degradation in dying cells, is investigated as an indicator of wound healing. The biosensor was fabricated by immobilizing uricase (UOx) natural catalyst for UA as the enzyme and, multi-walled carbon nanotubes (MWNT) and gold nanoparticles (Au) as electron exchange matrix. UA is oxidized by UOx with the Au nanoparticle and MWNT matrix providing thermodynamically feasible electron transfer pathways leading to the detection of byproduct H2O2, through its reduction on the matrix. This matrix was treated with cold plasma treatment which enabled sintering of Au nanoparticles on MWNTs, without damaging the substrate. This sintering induced densification led to higher conductivity of the matrix. The electrochemical results show that the treatment improved the H2O2 reduction peak potential (Epc) by 27% (from −534 to −392mV) for cold plasma treated matrix compared to untreated matrix. The biosensor has a linear range of 2.9 µM to 0.1 mM of UA with the sensitivity of 0.1 µA µM−1 cm−2 and the lowest detection concentration of 0.9 µM. These results show that this biosensor can be used to monitor UA in physiological concentrations.